Multistage centrifugal, turbine, or like pump.



No. 782,272. l PATENTED FEB. 14, 1905. E. RAY.

MULTISTAGE CBNTRIFUGAL,TURBINE,OR LIKE PUMP.

APPLICATION FILED 11211.30, 1904.

UNTTED STATES Patented February 14, 1905.

PATENT OEETCE EREDERlOK RAY, OE EAST ORANGE, NEY JERSEY, ASSIONOR TO HENRY R. WORTHINGTON, OF NEV YORK, N. Y., A OORlORA'llON OF NE\V JERSEY.

WlULTlSTAGE CENTRIFUGAL, TURBINE, OR LlKE PUMP.

SPECIFICATION forming part of Letters Patent No. 782,272, dated February 14, 1905.

Application filed April 30, 1904. Serial NoA 205,680.

Be it known that I, Ennnnnioii RAY, a citizen of the United States, residing at East Orange, coun ty of Essex, and State of New Jerseydlave invented certain new and useful Improvements in .llultistage Centrifugal, lurbine, or Like Pumps, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

lO This invention relates to an improved centrifugal, turbine, or like pump of that class having a plurality of inclosed impellers arranged in series and known as compound or multistage pumps; and the invention consists in an improved construction by which etlicient balancing' of the pump-pressures is secured.

ln accordance with the present invention the successive impellers are not separated by 2O the usual lixed diaphragms at the hub; but

the hubs of the successive impellers are provided with suitable balancing-surfaces on the delivery side, so that the delivery-pressure acts in opposition to the suction-pressure on the hub of each impeller, the surfaces sub- -jected to pressure on the delivery and suction sides of the impellers being' preferablyv substantially the same. The delivery-pressure of the last impeller of the series is preferably not applied to its hub; but the pressure upon the last impeller is preferably partially balanced so as to balance the suction-pressure on the tirst impeller and secure the complete balancing' of the shaft carrying the series of impellers, which may be done by a pipe connecting the suction of the lirst impeller with the balanoing-chamber at the rear side of the last impeller. The impellers are provided with flanges or shoulders forming running-joints 4o with the inner edges of the casing or diaphragms on the suction and delivery sides of the impellers, and outside vanes on the opposite side walls of the impellers are preferably used to prevent leakage past the running'- joints into the balancing-spaces at the hubs,

although this feature may be omitted.

For a full understanding' of the invention a detailed description of a construction embodying all the features of the same as applied in their preferred form to a common type ofcentrifugal or turbine plunp will now be g'iven in connection with the accompanying' drawings, forming a part of this specilication, and the features forming the invention will then be specilically pointed out in the claims.

ln the drawings, Figure l is a central section of the pump, taken longitudinally of the axis, a multistage pump having three impellers being' shown. Eig. l is an end view looking to the right in Fig. l with the casing and 6o suction broken away to show the end impeller.

Referring to the draw i ug's, A is the pump-casing, having the suction B and deliveryO and having' the three impellers D/ l)" D, which are carried by the driving-shaft E. These impellers D l)`i 1);; are all of a common inclosedimpeller form-that is, having the side walls 10 and vanes 1l extending between the side wallsand these impellers are shown as having on opposite sides outside vanos l2 on the 7c walls l0, running in chambers on the opposite sides of the impellers, these chambers preferably being' closed to the impeller-space bythe side walls of the impeller. As usual in this class of pumps, the lirst impeller 1.) takes its suction at the hub directly from the pumpsuction B and delivers through curved annular passage d, which extends inward to the hub and forms the suction of the second impeller D?, which in turn delivers through a similar curved SO annular passage d to the hub and suction of the third im peller D. Diffusion-rings 16 are preferably used outside the impellers and lixed vanes 1T in the passages fl di, extending to the inner edges of the diaphragms, as usual .85 in turbine-pump constructions. 'lhese impellers D' D" D, however, instead of being separated from their delivery-passages (Z di" at the hub by diaphragms, so that the delivery-pressure at the hub comes upon the diapln'agm and not upon the back of the impeller, are arranged to abut directly against each other, and the diaphragms l-l between the backs of the impellcrs and the deliverypassages d Z2 terminate at such a distance 9 5 outside the hubs, so that the pressure of the liquid in the passages d Z2 at the hub comes upon the rear side of one impeller and the suction side of the next impeller, thus providing balancing-surfaces at the hub on the rear or delivery side of the impellers. The end casings 13 and the diaphragms 14 between the successive impellers preferably terminate, as shown, on about the line of the interior edge of the impeller-vanes 11, and the impellerwalls 10 are provided on opposite sides with projecting flanges or shoulders 1, which form running-joints with the inner edges 2 of the end casings 13 and diaphragms 14. It will be seen that with this construction the pressure on the impellers outside the runningjoints 1 Qis balanced by the opposite side walls 10 of the inclosed impellers, and the pressures at the Vhub in the passages d (Z2, which form the delivery-passages for the impellers D D2 and the suction-passages for the impellers D2 D3, are balanced by the surfaces on the hubs of the successive impellers within the diaphragms 14, which are subjected to the pressure of the liquid. The shaft E, carrying the impellers, therefore, is entirely balanced, except that the suction-pressure on the impeller Dl is not balanced, but tends to move the shaft E to the right in Fig. 1, and this excess pressure is not counterbalanced by any pressure in the pump as thus far described. This excess pressure tending to move the shaft E and impellers to the right in Fig. 1 may be balanced by other means or in small pumps may be neglected; but preferably this pressure on the suction is balanced by a pipe connecting the suction B of the first impeller with the rear side of the last impeller. As shown in the drawings, pipe F connects the suction-pipe B with a balancing-chamber 15 on the rear side of the im peller D3, this chamber being formed so as to provide substantially the same area of pressure-surface as that subjected to pressure on the suction and /delivery sides of the other impellers.

/ The outside vanes 12 are preferably used kand aidlng in preventing' leakage from the outer edge of the impellers, inward outside the impeller, and past the running-joints 1 2. While the use of these vanes is desirable, however, and their combination with the broader features of the invention forms the subject-matter of specific claims, it will be understood that these outside vanes may be omitted within the invention considered broadly. These outside vanes when used preferably extend substantially from the outer edge of the impeller to the running-joint, as shown; but the length of these vanes may be varied so long as they are of suflicient length to prevent such inward pressure at the running-joint as will cause leakage past the joint into the space at the hub of the impeller.

The invention secures a very efficient balance of a multistage centrifugal or turbine pump under different running conditions. The construction also is simpler, cheaper, and more satisfactory than constructions in which the impellers are separated by diaphragms at the hub, less running-joints being required, lesseningthe expense for fitting parts and reducing the danger of leakage.

It will be understood that the invention is not limited to the exact form or construction of parts in the pump shown, but that the invention is applicable generally to multistage centrifugal or turbine .pumps of the inclosedimpeller type.

What I claim is- 1. In a multistage centrifugal, turbine or similar pump, the combination with a plurality of inclosed impellers having their suction at the hub on one side and balancing-surfaces on their deliverysides opposite the suction, of diaphragms between the im pellers and their delivery-passages terminating ou tside the balancing-surfaces on the delivery sides of the impellers.

2. In a multistage centrifugal, turbine or similar pump, the combination with a plurality of inclosed impellers having their suction at the hub on one side and balancing-surfaces on their delivery sides opposite the suction, of diaphragms between the impellers and their delivery-passages terminating outside the balancing-surfaces on the delivery sides of the impellers, and means for balancingthe excess of pressure on the suction side of the pump.

3. ln a multistage centrifugal, turbine or similar pump, the combination with a plurality of inclosed impellers having their suction at the hub on one side and balancing-surfaces on their delivery sides opposite the suction, of diaphragms between the impellers and their delivery-passages terminating outside the balancing-surfaces on the delivery sides of the impellers, a balancing-chamber on the rear side of the last impeller, and a pipe connecting said balancing-chamber with the pumpsuction.

4. In a multistage centrifugal, turbine or similar pump, the combination with a plurality of inclosed impellers having their suction at the hub on one side and balancing-surfaces on their delivery sides opposite the suction, of diaphragme between the impellers and their delivery-passages terminating outside the balancing-surfaces on the delivery sides of the impellers, flanges forming running-joints between the impellers and the casing and diaphragms, chambers on the opposite sides of the impellers outside said joints, and vanes carried bythe impellers running in said chambers.

5. In a multistage centrifugal, turbine or similar pump, the combination with a plurality of inclosed impellers having their suction at the hub on one side and balancing-surfaces on their delivery sides opposite the suction, of diaphragms between the impellers and their IOO IIO

IIS

D2, &c., of delivery and suction passages (Z, (Z2, Sac., diaphragins 14 between the impellers and their delivery-passages, and balancing-surfaces on the delivery sides of the impellers subjected to the pressure in seid passages, and balancing-chamber 15 on the last irnpeller,sub stantially as described.

In testimony whereofl I have hereunto set my hand in the presence of two subscribing witnesses.

l FREDERICK RAY. llTitnesses:

C. J SAWYER, lV. H. KENNEDY. 

